ICD-10 Code E77.0 – Defects in post-translational modification of lysosomal enzymes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E77.0 – Defects in post-translational modification of lysosomal enzymes
What it is
E77.0 identifies a genetic disorder in which lysosomal enzymes are not properly modified after they are made. This can prevent enzymes from reaching lysosomes and working normally.
Clinical signs
Clinical features vary; refer to documentation. Standard references describe a lysosomal storage disorder pattern, often with developmental delay, organ enlargement, and progressive neurologic or skeletal findings.
When to use this code
Use this code when the provider documents a defect in post-translational modification of lysosomal enzymes, including related inherited enzyme-processing disorders. Code it from confirmed diagnoses, genetic workups, or specialist assessments that clearly name this condition.
Do not assume it from nonspecific lysosomal disease, abnormal enzyme testing alone, or an unspecified storage disorder. If the record does not identify this exact defect, check documentation before assigning E77.0.
Do not use for
Do not use this code for other mucolipidoses, general lysosomal storage diseases, or isolated enzyme deficiencies unless the record specifically states post-translational modification defects. Check documentation.
Coding tip
Look for the exact clinician wording; this code is specific, and vague storage-disease terminology usually needs clarification.